package cn.edu.ctbu.ty01.service;

import cn.edu.ctbu.ty01.constant.REnum;
import cn.edu.ctbu.ty01.dao.StudentRepository;
import cn.edu.ctbu.ty01.entity.Student;
import cn.edu.ctbu.ty01.exception.RException;
import org.springframework.data.domain.Example;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Pageable;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class StudentService {

    @Autowired
    public StudentRepository studentRepository;

    public List<Student> getAll(){
        return studentRepository.findAll();
    }

    /**
     * 按ID进行查询
     * @param id 主键，整数
     * @return
     */
    public Student findById(Integer id){


        return studentRepository.findById(id).orElse(null);

    }

    /**
     * 按名字进行查询 Like
     * @param name 字符
     * @return
     */
    public List<Student> findByName(String name){


        return studentRepository.findByNameLike(name);

    }

    /**
     *
     * @param name
     * @param password
     */
    public List<Student> findByNameAndPassword(String name , String password){


        return studentRepository.findByNameAndPassword(name,password);

    }

    /**
     * 增加
     */
    public Student add(Student student){

        return studentRepository.save(student);
    }

     /** 更新学生
     * @param student
     * @return
     */
    public Student update(Student student){
        return studentRepository.save(student);
    }

    /**
     * 删除学生
     * @param id
     */
    public void delete(Integer id){
        studentRepository.deleteById(id);
    }

    public Page<Student> getAll(Pageable pageable){
        return studentRepository.findAll(pageable);
    }

    public Page<Student> getAll(Example<Student> example, Pageable pageable){
        return studentRepository.findAll(example,pageable);
    }



    public Student validateUsernameAndPassword(String sno, String password) throws Exception{
        List<Student> students = studentRepository.findBySno(sno);
        if(students.size()>0){
            Student student = students.get(0);
            if(student.getPassword().equals(password)){
                return student;
            }
            else{
                throw new RException(REnum.LOGIN_ERR);
            }
        }
        else{
            throw new RException(REnum.LOGIN_ERR);
        }
    }
}
